The present invention relates to a paper web folding and cutting apparatus particularly for a form printing press.
In a form printing press, a continuous web of paper is fed in a predetermined direction and, during this feeding, the continuous web of paper is sequentially printed and worked. Thereafter, the continuous web of paper is folded in a zigzag fashion by a folding and cutting apparatus including an oscillatory shooter assembly and is then cut into a predetermined number of pieces, of having a sheet or strip shape, and are then discharged.
The folding and cutting apparatus has a structure in which the continuous web paper is swung bilaterally by the oscillatory shooter assembly which swings bilaterally like a pendulum in a perpendicular plane, and according to such motion of the oscillatory shooter assembly, the continuous web of paper is worked or bent in a zigzag fashion at the folded portion, and then the paper is then piled.
The folded and piled continuous web of paper is thereafter cut into a predetermined number of sheets such as 500 sheets in one set, discharged on a conveyer, then packaged and shipped.
In a conventional form printing press, in order to fold the continuous web of paper, it is always required, at the working section, to form a cross line of perforations to top and bottom positions for folding of the continuous web paper for one sheet or strip before feeding to a folding apparatus and it is then folded by the folding apparatus. For example, Japanese Patent Publication No. HEI 8-18750 discloses a technique such that the continuous web of paper is automatically cut by means of a cutter knife along the cross line of perforations with a timing coincident with the folding of the continuous web of paper in the predetermined number of sheets, or Japanese Utility Model Laid-open Publication No. HEI 5-41811 discloses a technique such that the continuous web of paper is folded in a predetermined number of sheets and, then, the folded continuous web paper is cut along the cross line of perforations by pressing, against the continuous web of paper, a press roller and a tension roller rotating at a peripheral speed which is faster than a traveling speed of the continuous web of paper and then pulling the continuous web of paper to cut the same. Furthermore, Japanese Patent Laid-open Publication HEI 9-76460 discloses a technique in which cuts or notches are formed on and along the cross line of perforations of the continuous web of paper in an overlapped manner in coincidence with a timing of every predetermined number of sheets of the folded continuous web of paper. And, thereafter, a roller rotating at a peripheral speed which is faster than a travelling speed of the continuous web of paper is pressed against the continuous web of paper to thereby cut along the cut and the cross line of perforations.
As mentioned above, in the conventional folding and cutting apparatus of the form printing presses, it is always necessary to form cross lines of perforations to in the continuous web of paper, and then fold and cut the web along the cross lines of perforations.
However, in the conventional techniques mentioned above, the folding line coincides with the cross line of perforations, and hence, the thickness of the folded portion becomes larger than a combined thickness of two sheets of the continuous web of paper (called hereinlater, continuous paper web or simply paper web). Therefore, a set product of the folded and discharged continuous paper web has a protuberant portion at the folded portion along the cross line of perforations (i.e. both ends in the width direction of the folded paper web) and an upper surface of the product will be curled. If such curled product is fed for the next working such as bookbinding working, a certain trouble will be caused. Accordingly, in order to eliminate such trouble, it has been required to press down the curled portion manually or with pressing means so as to flatten the upper surface of the set product.
Furthermore, in a case where the cuts or notches are newly formed on the cross line of perforations, it is necessary to prepare, in addition to a cross line perforation forming means, a cutting means for forming the cuts and a control means for controlling the operations of contacting or separating the cutting means to or from an impression cylinder of a printing press, which will result in an undesired increase in costs.
An object of the present invention is to substantially eliminate defects or drawbacks encountered in the prior art mentioned above and to provide a folding and cutting apparatus of a form printing press, without the necessity of forming cross lines of perforations, capable of preventing a formation of a protuberant portion at a folded portion of a set product, which is then cut and discharged to thereby prevent any curled portion from being formed and easily cutting a continuous web of paper at predetermined positions.
This and other objects can be achieved according to the present invention by providing a paper web folding and cutting apparatus, comprising:
a paper web traveling path enabling a continuous paper web to travel at a predetermined traveling speed;
a cut portion forming means disposed on the paper web traveling path and adapted to form a cut portion formed as a line of a plurality of cuts, having at least one uncut portion, at every top and bottom directional dimension of the continuous paper web to be folded; and
an oscillatory shooter assembly disposed on the paper web traveling path at a portion downstream side of the cut forming means in a paper web traveling directions. The oscillatory shooter assembly is provided with a counter roller and a nozzle roller at a lower end portion thereof. The counter roller and nozzle roller are rotated at a peripheral speed that is faster than the paper web traveling speed. The nozzle roller is contacted to and separated from the counter roller, and the oscillatory shooter assembly performs an oscillatory motion in a bilateral direction in a state that the continuous paper web is interposed between the nozzle roller and the counter roller so as to fold, in a zigzag fashion, the continuous paper web along the cut portions.
The continuous paper web is cut along the cut portions by pressing the nozzle roller against the counter roller at a timing just prior to when the cut portion to be cut approaches an upstream side portion of both the nozzle roller and counter roller.
In a preferred embodiment, the cut portion forming means for forming a cut portion comprises a paper web cut path disposed on an upstream side of the oscillatory shooter assembly and a cut cylinder assembly composed of an impression cylinder and a cut cylinder which are arranged on both sides of the paper web cut path in an opposed manner. The impression cylinder and the cut cylinder have substantially the same diameter and are rotated at the same peripheral speed in a paper web traveling direction with the continuous paper web being interposed therebetween. A cutting blade is mounted on the cut cylinder so as to extend in a longitudinal direction thereof for forming a line of cuts as the cut portion along which the continuous paper web is folded and cut. The cutting blade is formed with at least one cutout for forming at least one uncut portion at the cut portion.
The nozzle roller is supported by a frame member through a bearing means so as to be rotatable and a rotational center of the bearing means with respect to the frame member is offset from a rotational center of the nozzle roller.
The folding and cutting apparatus further includes a controller for controlling the timing for pressing the nozzle roller against the counter roller. The nozzle roller is pressed against the counter roller at a timing when a plurality of set sheets of the continuous paper web are folded by the oscillatory shooter assembly.
The folding and cutting apparatus of the characters described above is particularly applicable to a form printing press.
According to the present invention of the structures described above, the portion of the continuous paper web to be folded by the oscillatory shooter assembly is composed of a cut portion of a line having a long cut-in length and a small uncut portion in comparison with the formation of a cross line of perforations, which is a line composed of continuous fine holes, so that the continuous paper web can be bent and folded with no protuberant portion at the bent portion. The set of products discharged after the cutting do not produce any expanded or protuberant portion as well as no clearance, in which air may stay, between the piled folded portions, thus providing a product with no curl. Accordingly the operations and workings can be made easy and simple and members or parts to be used, such as a perforated cross line forming device, can be effectively reduced.
Furthermore, the continuous paper web can be easily cut at a predetermined portion along the long cuts.